1. Field of the Invention:
This invention relates to an auto-lock slider for use in an ordinary-type slide fastener, and more particularly to an auto-lock slide fastener slider in which a locking pawl of a locking leaf spring is brought into and out of engagement with fastener elements in response to pivotal movement of a pull tab between a horizontal posture and an upright posture.
2. Description of the Related Art:
FIG. 7 of the accompanying drawings shows a conventional auto-lock slide fastener slider of the described type as disclosed in, for example, Japanese Utility Model Publication No. Sho 54-43841. In the conventional slider, a leaf spring 2' has a central base 7' concealing an eccentric axle of a pull tab, a locking pawl at a rear end of the central base 7', and a small-width front end portion 9' downwardly bent centrally from a front end of the central base 7' and fixed to a front surface of a guide post 6' of a slider body 1'. The spring 2' has at opposite sides of the front end portion 9' of the central base 7' a pair of shoulders, which are pivotally movably engages with a pair of sloping spring seats 12' projecting from an upper wing 4' of the slider body 1', and at the rear end of the central base 7' an opening whose edge is engageable with an engaging lug 15' standing on the upper wing 4'. By the action of a cam 29' formed on the axle 10' of the pull tab 3', the locking pawl of the spring 2' is brought into and out of engagement with fastener elements in response to pivotal movement of the pull tab 3' between a horizontal posture and an upright posture.
FIG. 8 shows another conventional auto-lock slide fastener slider as disclosed in U.S. Pat. No. 5,031,286. In this conventional slider, a leaf spring 2" has a central base 7" concealing an eccentric axle 10" of a pull tab 3", a locking pawl 8" at a rear end of the central base 7", a small-width front end portion 9" projecting centrally from a front end of the central base 7", a pair of front engaging strips 24" downwardly bent from opposite sides of the front end of the central base 7" and engageable with a pair of front sloping engaging lugs 12" on the upper wing 4", and an opening 26" near the rear end of the central base 7" through which opening 26" a rear engaging lug 15" on the upper wing 4" is loosely threaded. In response to pivotal movement of the pull tab 3" between a horizontal posture and an upright posture, the locking pawl 8" of the spring 2" is brought into and out of engagement with fastener elements.
In the conventional auto-lock slide fastener slider of FIG. 7, partly since the leaf spring 2' on the upper surface of the upper wing 4" is bent, and partly since the spring seats 12' project from the upper surface of the upper wing 4', the upper side of the slider is uneven and hence unsightly in appearance, and also, when the slider is pulled along a pair of rows of fastener elements, the spring seats 12' might strike something nearby and get damaged. Further, since the pull tab 3' is merely placed on the slider body, the total height of the slider is large to make the slider not stylish.
In the conventional auto-lock slide fastener slider of FIG. 8, since the leaf spring 2" is merely placed on the slider body and is supported by its own resilience, the fixing of the leaf spring 2" on the slider body is unstable. Further, since the spring 2" itself is bent at the axle 10" of the pull tab 3" to project from the upper surface of the upper wing 4", the design of the resulting slider is undesirable. And since the pull tab 3" also is merely placed on the slider body, the total height of the slider body is large to make the slider not stylish.